<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8" />
        <meta http-equiv="X-UA-Compatible" content="IE=edge" />
        <meta name="viewport" content="width=device-width, initial-scale=1.0" />
        <title>类中的方法this指向</title>
    </head>
    <body>
        <script type="text/javascript">
            class Person {
                constructor(name, age) {
                    this.name = name;
                    this.age = age;
                }

                speak() {
                    console.log(this);
                }
            }

            const p1 = new Person("Tom", 18);
            p1.speak(); // 通过实例调用speak方法，this指向调用的实例

            const x = p1.speak;
            x(); // 未通过实例调用speak方法，this是undefined
        </script>
    </body>
</html>
